1. Field of the Invention
This invention relates to an air bag suppression system and more particularly to a dual stage air bag system dependent on seat position.
2. Description of the Related Art
It is well known in the art to provide a supplemental inflatable restraint (SIR) system for the protection of vehicle occupants. A typical SIR system includes a housing, an air bag normally stored in the housing, and an inflator for discharging gas to inflate the air bag. Conventional systems activate the inflator in response to a predetermined amount of deceleration.
Some systems incorporate a dual stage inflator system. These systems control the inflation of the air bags in response to the severity of a collision. A first or low stage inflation having a low volume is activated in a collision with lower deceleration. A second or high stage inflation having an increased volume is additionally activated in collisions with higher decelerations. Typically a deceleration sensor senses the deceleration of the vehicle during a collision. The first inflation stage is triggered in response to the output of the deceleration sensor when the detected deceleration is equal to or greater than a first threshold value. The second inflation stage is triggered in response to the output of the deceleration sensor when the detected deceleration is equal to or greater than a second threshold value higher than the first threshold value.
U.S. Pat. No. 5,803,491 discloses an air bag disabling system for completely disabling the deployment of the air bag when the seat is in certain forward positions and is hereby incorporated herein by reference. When this air bag system is completely disabled, the air bag system is disabled and does not deploy.
The dual stage air bag provides certain deployment options over the single stage air bag inflation systems. It may be advantageous to control the deployment of the first and second stages, not only upon vehicle deceleration, but also based upon the seat position.